tests: fix test-profile to not depend on HGPROF environment variable

The test-profile test would fail if the user had HGPROF set to another
profiler in their environment.  This fix makes the test independent of
that environment variable.

Reverts the previous attempt to fix this, which was not cross platoform.

tests/run-tests.py

@@ -1277,6 +1277,9 @@ def main():
         # can't remove on solaris
         os.environ['HG'] = ''
         del os.environ['HG']
+    if 'HGPROF' in os.environ:
+        os.environ['HGPROF'] = ''
+        del os.environ['HGPROF']
 
     global TESTDIR, HGTMP, INST, BINDIR, PYTHONDIR, COVERAGE_FILE
     TESTDIR = os.environ["TESTDIR"] = os.getcwd()

tests/test-profile.t

@@ -8,8 +8,6 @@ test --time
 
 test --profile
 
-  $ export -n HGPROF
-
   $ hg --profile st 2>../out
   $ grep CallCount ../out > /dev/null || cat ../out